Du H, Zhang W, Littlejohns C G, Stankovic S, Yan X, Tran D T, Sharp G J, Gardes F Y, Thomson D J, Sorel M, Mashanovich G Z, Reed G T
Opt Express. 2019 Mar 4;27(5):7365-7372. doi: 10.1364/OE.27.007365.
In this paper, we report the generation of an ultra-sharp asymmetric resonance spectrum through Fano-like interference. This generation is accomplished by weakly coupling a high-quality factor (Q factor) Fabry-Pérot (FP) cavity and a low-Q factor FP cavity through evanescent waves. The high-Q FP cavity is formed by Sagnac loop mirrors, whilst the low-Q one is built by partially transmitting Sagnac loop reflectors. The working principle has been analytically established and numerically modelled by using temporal coupled-mode-theory (CMT), and verified using a prototype device fabricated on the 340 nm silicon-on-insulator (SOI) platform, patterned by deep ultraviolet (DUV) lithography. Pronounced asymmetric resonances with slopes up to 0.77 dB/pm have been successfully measured, which, to the best of our knowledge, is higher than the results reported in state-of-the-art devices in on-chip integrated Si photonic studies. The established theoretical analysis method can provide excellent design guidelines for devices with Fano-like resonances. The design principle can be applied to ultra-sensitive sensing, ultra-high extinction ratio switching, and more applications.
在本文中，我们报道了通过类法诺干涉产生超尖锐非对称共振光谱。这种产生是通过倏逝波将高品质因数（Q 因子）法布里 - 珀罗（FP）腔与低 Q 因子 FP 腔弱耦合来实现的。高 Q FP 腔由萨格纳克环形镜形成，而低 Q FP 腔则由部分透射的萨格纳克环形反射镜构建。利用时间耦合模理论（CMT）对工作原理进行了分析推导和数值建模，并使用在 340 nm 绝缘体上硅（SOI）平台上通过深紫外（DUV）光刻图案化制造的原型器件进行了验证。已成功测量到斜率高达 0.77 dB/pm 的明显非对称共振，据我们所知，这高于片上集成硅光子学研究中最先进器件所报道的结果。所建立的理论分析方法可为具有类法诺共振的器件提供出色的设计指导。该设计原理可应用于超灵敏传感、超高消光比开关及更多应用。
